新型纵向流一体式翅片管换热性能数值模拟

为达到提高壳侧传热系数的同时又具有较低的压力损失的目的,提出了新型纵向流一体式翅片管。针对翅片与管壁夹角的变化影响传热效率的问题,根据有无翅片、翅片夹角的不同、翅片种类的不同,利用计算流体力学(CFD)软件建立了7种周期性单元流道,并对壳侧流场和传热场进行了三维数值模拟,分析了不同流速的介质在流道中的扰动、压降及温度变化。模拟结果表明,在所有的翅片管中翅片夹角为105°翅片管的换热系数最高,翅片夹角为105°翅片管换热系数约为光管的1.4—1.6倍,压降仅为横向掠过的圆形翅片管的0.018—0.15倍。翅片夹角为105°时,翅片管综合性能较优,对烟气换热器应用提出了数值保障。

Numerical simulation of heat transfer performance of new longitudinal-flow-integrated finned tube

Considering the effect of changes of angle between fins and wall of longitudinal-flow-integrated finned tube on heat transfer efficiency,7 kinds of periodic unit channels were established according to the conditions with or without fins,different angles and fins by using computational fluid diagram(CFD).Three-dimensional numerical simulation was conducted for the flow and heat transfer field in shell side.The changes of disturbance,pressure drop and temperature of medium were analyzed with different velocity in flow channel.The simulation results show that the heat transfer coefficient of finned tube with fin angle of 105° is the highest of all finned tubes,which is about 1.4-1.6 times that of plain tube.Its pressure drop is about 0.018-0.15 times that of round fin tube.The comprehensive properties of finned tube are the best when fin angle is 105°,which provides numerical guarantee for the application of smoke finned-tube heat exchanger.